The Meyer Shank driver loses it out of the corner and hit the wall - Siegel had nowhere to go.
Pato O'Ward wins with the big boss Zak Brown watching on, he even had a few victory laps under Caution.
Siegel and Rosenqvist have tangled and brought out a late yellow.
There's only a few tenths between them with two laps to go.
He's involved in several different touches with cars including Conor Daly, Felix Rosenqvist, and Marcus Armstrong.
Rosenqvist and Lundgaard both narrowly avoid hitting the wall. It's inches from another Caution.
These are some great moves from Malukas - he's passed a whole group of cars who are struggling on old tyres.
He's not thinking about the championship anymore as he narrowly avoids the wall trying to pass Lundgaard. This allows Malukas through and into 12th.
He rejoins just in front of Palou who quickly dispenses of him. Power tries the same but gets stuck behind.
Not quite able to get it down, Malukas drops behind Power in 15th.
David Malukas sits in third and might have to pit again before the end - this would give Kyffin Simpson his first podium.
O'Ward has a 2.5s gap now, This could be his second win in two weekends.
O'Ward is managing that gap at the front well - the current result would drop Palou's championship lead below 100 points again.
Herta has pitted again and is down in sixth and nine seconds off the lead.
Not the race anyone thought would happen with your expected front runners so far badly hurt by all the cautions.
both Palou and Dixon seem to be out of the chance to win. Herta still could with a Caution.
Ericsson has pitted from second promoting O'Ward. Herta leads but does need to pit again.
O'Ward comes in - he comes out ahead of Veekay! Simpson pits too and is behind of Veekay and Sting Ray Robb.
O'Ward stays out - will he respond next lap?
Dixon is back into the pits and comes out ahead of Palou.
Seems to be early but it gives him free air.
Lundgaard comes in to change tires and for more fuel.
Somehow despite his spin, Kirkwood is right behind Herta. Impressive stuff from him today.
There's lots of different strategies going on today, Veekay could extend this stint and only pit once more which would mean he is still in the hunt for this win.
Palou is slicing through the field and is 13th while Herta is in 10th.